[Late ventricular potentials: significance, electrophysiology and clinical importance in coronary disease].

Ventricular late potentials are high-frequency, low-amplitude abnormal electrical signals occurring in the terminal QRS complex or on the ST segment of the electrocardiogram during sinus rhythm. They are thought to represent delayed activation of some areas of a diseased myocardium and are therefore considered as a marker of an arrhythmogenic substrate, especially in patients after myocardial infarction. An association between the presence of ventricular late potentials and the occurrence of malignant re-entrant ventricular arrhythmias has been clearly demonstrated, and the prognostic value of late potentials after myocardial infarction has been confirmed by several large prospective trials. Because it is a simple and noninvasive technique, the detection of ventricular late potentials allows a first risk stratification of postmyocardial infarction patients, together with the Holter recording, the exercise stress test, the echocardiography and the radionuclide ventriculography. Such a risk stratification strategy is essential because the empirical use of antiarrhythmic drugs has been associated with an adverse prognosis and because significant advances have been made in the management of malignant ventricular arrhythmias. The clinical value of ventricular late potentials is mainly related to their negative predictive value (93 to 98%), and their positive predictive value has been shown to be low (6 to 19%). But even if the prognostic value of late potentials after myocardial infarction is now well established, their exact role for the management of individual patients still needs to be defined.